Air compressor



Sept. 16, 1958 INTAKE R. c. STOLTE 2,852,184-

AIR COMPRESSOR F iled May 27, 1957 INVENTOR.

fla 151M W6 A 7'TORNE'V United States Patent AIR COMPRESSOR Richard C. Stolte, Birmingham, Mich., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application May 27, 1957, Serial No. 661,646

7 Claims. (Cl. 230-181) This invention relates to a multistage radial air compressor.

An object of this invention is to provide a multistage air compressor having one stage including a plurality of cylinders and pistons with a second stage comprising a single cylinder and piston.

A further object is to provide a multistage air compressor with a single connecting rod or crank for actuating all of the pistons in the severalstages.

A still further object is to provide a multistage air compressor having a plurality of cylinders and pistons all positioned in a common radial plane to provide a minimum thickness for economical installation.

Also, it is an object of this invention to provide a multistage air compressor having at least one stage with its piston members being of the inverted type and with allof the stages having pistons removable at their outside ends for greater accessibility and ease of repair.

Other features, advantages and objects will become apparent by reference to the detailed description of the invention and to the drawings wherein;

Figure 1 is a detailed cross-sectional view of an air compressor embodying this invention, and

Figure 2 is a cross-sectional view of the annular disk member together with its valve, as seen in the direction of arrows 2-2 of Figure 1.

Referring now to the drawings and more particularly to Figure 1, an air compressor is shown having a housing 12 of such a shape as to define a plurality of cylinders 14, 16 and 18 radially disposed with respect to a drive shaft 20 and equally spaced circumferentially from each other. Within each cylinder, 14, 16 and 18 is slidably disposed a piston member 22, 24, 26, respectively, cylinders 16 and 18 together with their pistons 24 and 26, respectively, constituting a first stage of compression, with cylinder 14 and its piston 22 constituting a second stage of compression. Pistons 22, 24 and 26 each are of generally U-shaped design and have a face portion 28 and a hollowed out or bored portion 30. The piston 22 is used in a normal manner and has its face portion 28 adapted to compress air in a chamber 34. The pistons 24 and 26 in the first stage are of the inverted or insideout type and have their bored or concave portions 30 adapted to compress the air in chambers 36. A plurality of ring members 32 are provided for the well known purpose of preventing the escape of air from the chambers 34 and 36.

The pistons 22, 24 and 26 are operably connected to the drive shaft 20 by means of a connecting rod or crank 38 rotatably mounted for oscillation in the well known manner on an eccentric 40 fixed for rotation with drive shaft 20. The connecting rod or crank has an extension or projection 42 connected to piston 22 by means of a ball and socket universal joint 44. The lower circular hub portion 45 of the rod or crank 38 is formed as a cam member on its outer rim against which faces 28 of pistons 24 and 26 are adapted to bear. Spring member 48, positioned between a portion 49 of a cylinder cap 51 Patented Sept. 16, 1958 2 and the piston 24, is provided for biasing piston 24 into engagement with the circular cam 45. A similar spring (not shown) also biases piston 26 into engagement with cam 45.

Referring more particularly to Figures 1 and 2, the valving mechanism for controlling the air intake and exhaust will now be described. Since both of the cylinders in the first stage of compression are of a similar construction, only one ofthe valve mechanisms will be described. Referring to Figure 1, the cylinder 16 is formed with an open end 50 adapted to be closed by means of an annular plate member having a boss 52 formed thereon for projecting into the bore 30, the plate and boss having a plurality of passages or bores 54 and 56 and a valve recess or pocket 58. Overlying plate and boss 52 is an annular metallic disk member 60 having an air passage 62 and a flexible tongue-like or reed valve portion 64. A spacer 66, provided with suitable air passages 68, is superimposed on disk 60 to separate this disk and a second disk 70 also having an .air passage 72 and a flexible valve portion 74. A cover or cap 76, provided with air passages 78 and 80 and a valve pocket 82, overlies disk 70, and the cover 76, disk 70, spacer 66, disk 60, and the plate and boss 52 are attached to housing 12 by any suitable fastening means 84 (Fig. 2). The valve portion 64 acts as a one-way check or flap valve permitting the intake of air into passage 56 by movement of the flexible portion 64 into the recess 58 while preventing return movement of air from passage 56 by seating of the valve portion against portion 86 of the spacer 66. Valve portion 74 acts in a similar manner permitting the exhaust of air from passage 54 to passage 80 but preventing returning movement thereof by seating of the valve portion against portion 88 of spacer 66.

While a set of intake and exhaust conduits or passages are shown for only one cylinder, it is to be understood ond stage are not shown since they form no part of this invention.

Operation Referring now to the operation of the air compressor embodying this invention, rotation of drive shaft 20 and eccentric 40 in a clockwise direction as seen in Figure 1, will cause oscillation of crank 38 to draw piston 22 downwardly from the piston shown causing air to be drawn into chamber 34 through the intake conduit (not shown). At the same time, in cylinders 16 and 18 of the first stage of compression, the cam 45 on the crank 38 will move piston 26 radially outwardly through its compression stroke with piston 24, which is spaced from piston 26 in phases of operation, moving through the final stages of its intake stroke. At this time, exhaust valve 74' is sucked closed against the shoulder 88 of the spacer member and the intake valve 64 is opened by being moved into the recess 58 to permit air to be drawn into chamber 36.

Upon continued oscillation of crank 45, piston 26 will move further through its compression stroke with piston 24 beginning its compression stroke. At this point, the air in chamber 36 will be compressed and forced through passage 54 opening valve 74 by moving it into the recess 82 while forcing intake valve 64 to close abutting shoulder 86 of the spacer member. The compressed air in passage 54 is then delivered to chamber 34 through suitable conduits (not shown).

After the crank 38 has reached its low dead center position, piston 22 will begin its compression stroke and the air supplied from pistons 24 and 26 will be compressed-again by piston-22. The compressed air will then be delivered from the-second stage piston 22 .through. its exhaust port and valve (not shown) to the mechanism to be actuated (not shown).

From-the; foregoing it twillt be seen athat the applicant 5 haseprovidedta. multistagesair.scompressor in which all: piston members are operatediby-a singlezoscillatingcmem-t. her, and all of the stages are in a common radial planes to --p.ermit. :a construction -wherein.- the: overall :thickness-is a mini-mum'thereby' conserving space. It will; be runder 1O stood 1that-,-the'invention can beFmOdified-"beyQnd the i1 lustratedcernbodiments, and therefore,any-1imitations to be-imposed are: those set-forth".- in the following;c1airns I claim:

1; In- =a tmultistage comprcssor, aedrive shaft, first-ands second "stage compression means, said first stage comprising;a :plurality of. tcylindess each-having a movable piston therein; saidtcylinders being. positioned-radially of said drive shaft and. spacedcircumferentiallyfrom each other,

said- -second stage comprisingsa single-cylinder having a-- 0 piston therein and being positioned medially of-said shaft-- and spaced'circumferentially from said -other---cy1inders-,

connecting rod means rotatably-mounted =on said drive shaft and connecting said! shaft andsaidsecond-stagepiston, said rod-means being eccentricallymounted onsaid drive shaft; andbias means-for yieldably engaging said first stagepistons-with said connectingrodfor movement; of.- said first-stage pistons by saidrod 'uponrot-ation of-said-driveshaft, said first-stage pistons-having faces-directly abutting-saidconnecting rod means. a

2: A- compressor-having first andsecond-stages of cornpressioncomprisinga drive shaft; a housing surrounding said 'drivetshaft, said housing being formedwith a plufl ralityof cylinders positioned radially from said drive. shaft and spacedcircumferentially from each" other, a piston in, each-of said cylinders, and a connecting-crank rotatably and eccentr-ically mounted on said drive shaft, said crank having one portion pivotally connectedwith one of ,said' pistons, and other portions of'said crank, directlycngaging the faces of the otherpistons, said second stagecolm prising a compression movement of th at pistqmpiyotally connected to said crank, said first stage ofcornpression comprising a compression, movement offthe. remaining pistons engaged-by the other portions ofj said'crank, rotationof'said drive shaft causing movement of all ofjsaid pistons by said crank.

3. A multistage compressor comprising, a housing, a drive. shaft, and a plurality of cylinders -insaidghousing,

said; cylinders being positionedrradially-of said-driyeshaftl and, spaced, from each other, an. eccentric fixed: to! said a shaft, pistons in said cylinders; and-a connecting-crank 4; Amultistage compressor havinga drive-shaft, and

anfeccentrie mounted on said drive shaft; a housingenofscylinders pistons-in.-said--cylinders, and -a--connecting-- crank rotatably mounted on said eccentric for moving said pistons upon rotation of saidshaft, said crank having a hub portion surrounding said eccentric and a projecting portion, one of said pistons being attached to said projecting portion, and meang for biasing said other pistons into abutting relationship with said hub portion, said compressor having a secondstageof-compression comprising movement of ,saidattached piston, with-a first stage-comprising movementofi said otherpistons by said hub po tion.

5. A multistagecompressgn as described, in ,claim 4, Wherein-said-pistenshave a face-portion and a concave portion, said crank;being attaghed -to the concave portion of said one piston, said other pistons having their face portions abutting the hub of said crank.

6. A two stage radial gas compressor comprisinga drive shaftg-a housing-enelosing'said shaft; an-eccentric on said shafha plurality of cylinders in said housing spacedjrom eaohyotherand-positibned== inacommon plane, pistons slidably-mounted insaid cylinders, and means connecting said-pistonsand-*said-eccentric for movement of said pistons upon rotation of said driveshaft, said means including a-cranlg mounted for oscillation on said eccentric,

saidcranlohaving aplurality of'portions adapted to engage a plurality of pistons, means for pivotally connecting 9 9f of e rer Q a dr k; th e .Q i p t ns t saidlother por f di ank'h v ns ramm n urf ces, formed integral therewith in, abutting relationship with e s of a d p n csa d i tqnsn av s. ons v n t:

e and L face p ons e J me is on bein o ne ed to the concave portion of said cranlc said, other portions ions f a dc the of *saidwranlgi abutting ti 1 e face port pistons, Y said first stagecornprisingl a simultaneous com: pression of gas, by saidother pistons, said second ,stage comprising a compression of {gas by said one, piston,

72* A two stage radiahgas, compressor comprising, a,

drive a t t a s ntric t xedt a aid hafta plurality i cylinders positionedjradially fromsaiddrive shaft and pa 9mJah h tn stQns movable. n said. cy nde d f onnecti renkim nnte ,v oe sc la ion. .0 1 aid. eccentric for connecting said pistonsand said-driveshaft,

iicrauk. het ns, ,po .t onsinteg al; he h a t n meit aiehpis q of as y aid mech ni l QH WtedPi m efere res it din he c otlh tpe en ZN TEQ. STATES: PATENTS;

335,530:- Lynn- Feb; 2, 1886 1367,7201! Scott Feb. 8, 1921' 1,627,031: Harris-u May 3, 1927 2,555,809 Naab- June 5, 1951 FOREIGN A EN 5112,1311 France,- Apr. 15, 1946 on oppos itfi sidfi. 0f said cranlg said ank; avin .aaiqalt wnne, on, t a o h stpi q e aidfir t tasefl omp sing;a m lta eousmpr s qnr tgas. by} aidt r tnam drPis s. abutting; saidcrank' said second stagecornprisinga compression- 

